In laser ignition systems, a pumped light source and an ignition laser are spatially separated from one another because the ignition laser must be situated in the immediate proximity of the combustion chambers of the internal combustion engine, and because the vibrations and operating temperatures of the internal combustion engine have a negative effect on the service life of the pumped light source. An optical fiber is present between the pumped light source and the ignition laser to span the distance between the pumped light source and the ignition laser. This optical fiber transports the pumped light generated by the pumped light source to the ignition laser. At that location the actual ignition pulse is generated in a solid-state laser, and is guided into the combustion chamber through a focusing lens and a combustion chamber window. The intended ignition plasma which triggers the combustion of the air/fuel mixture present in the combustion chamber is generated at that location.
The pumped light source and the optical fiber have long service lives of approximately 30,000 operating hours, while the ignition laser has a much shorter service life and must have maintenance at much shorter intervals. It is therefore necessary to be able to easily separate the optical fiber and the ignition laser from one another.
Fiber optic plug-in connector systems are discussed in WO 02/071122 A1 and EP 0 570 652 A2, in which a plug has an arrangement for closing the plug, and the arrangement may be opened as necessary. These plug-in connector systems operate using guide grooves and a slide control for the arrangement for closing the plug. These types of systems are therefore comparatively complex in their manufacture, and do not have the robustness required for operation under harsh conditions in the engine compartment of a motor vehicle.
In addition, for this plug-in connector system only one approach is described for protecting the optically active surfaces inside the plug or the optical fiber which ends in the plug. Protection of the optically active surfaces of a socket which is compatible with the plug is not described in the cited related art.
Dust and dirt are present in the engine compartment of a motor vehicle. Since both the optical fiber and the ignition laser are sensitive to soiling of their optically active surfaces, there is a need to provide a fiber optic connector system which in the separated state prevents soiling of the optically active surfaces of the plug and socket.